SAN DIEGO – Even though the Mets had done some nice things during a recent six-game winning streak, they still hadn’t figured out the one question that will haunt them through the winter: Who’s the closer?

Mike Stanton, the latest “hot hand” that manager Art Howe hoped to ride until Sept. 28, coughed up a potential Tom Glavine victory by surrendering a two-run homer to Phil Nevin in the bottom of the eighth last night. The Mets lost 3-2 and it was a sour-tasting defeat to open a nine-game road trip after the sweet success of their latest undefeated homestand.

When Howe removed Glavine from last night’s game with two outs in the seventh inning and his club ahead 2-1, it was a questionable decision. He did it only after a long conference with Glavine and the infielders, choosing to remove the 37-year-old lefty after 111 pitches.

Glavine allowed six hits and one earned run, continuing a streak that has helped him turn around his disappointing season. But David Weathers entered and turned around switch-hitter Gary Matthews Jr., a free-swinging leadoff hitter.

Weathers fell behind Matthews 3-and-1 and almost lost him, but third-base ump Gary Cederstrom said Matthews went around on the fifth pitch of the at-bat. Weathers then froze Matthews on a 90 mph pitch down the middle, but he didn’t come out to open the eighth.

With lefty Mark Kotsay leading off, Howe went with the left-handed Stanton (2-5). He retired Kotsay, but walked righty Mark Loretta and served up a full-count gopher ball to Nevin, who crushed it to right-center. It was Stanton’s second blown save in five tries.

Even though last night’s Mets-Padres game probably registered the same TV rating as the long-defunct Magic Johnson Show, there was plenty of action in the meaningless August game between two last-place teams.

Rookie Marco Scutaro, fighting for playing time at second base, broke a 1-1 tie in the fifth with a homer to center off righty Kevin Jarvis.

Working on three days’ rest, Glavine displayed the All-Star stuff over 6″ innings that had him headed to Cooperstown before this year’s detour through Flushing. He was in line for his 251st career win before Nevin attacked.

Maybe the key sequence in the game happened in the first inning, when Jason Phillips’ speed, or lack thereof, got him into trouble again. In front of his hometown friends and family, the slow-footed Phillips was thrown out at the plate.

The 26-year-old first baseman, among league leaders in grounding into double plays, was gunned down by center fielder Kotsay on an RBI single by Timo Perez.

Perez drove in Mike Piazza with a single through the middle of the infield, but Phillips was the victim of a perfect one-hop throw from Kotsay and an excellent block of home by catcher Gary Bennett. Bennett, a former Met, had his left cleat blocking the dish.

Phillips, a moonlighting catcher himself, should’ve known better than to slide into Bennett’s foot. Although it appeared he may have moved Bennett’s foot and found the plate (or touched it with his other foot), highly regarded plate ump Chuck Meriwether immediately called Phillips out. Phillips protested, and then Howe argued, but to no avail.

The Padres tied the game in the third after a leadoff single from Jarvis. Kotsay tripled into the right-field corner.